1. Field of the Invention
The present invention relates to the field of telecommunications services management. To be more precise, it relates to the management of telecommunication services using policy rules. The invention applies particularly well to networks using protocols of the Internet Protocol (IP) family or other protocols of higher level.
2. Description of the Prior Art
Such networks provide services of various types, including virtual private networks (VPN), videoconferences, etc.
The provision of these services impacts on the behavior expected of the network. The expected behavior can include compliance with a particular quality of service (QoS) associated with the service. In this case, the quality of service is negotiated between at least the operator of the telecommunication network and the provider of the service, in the form of a service level agreement (SLA). The SLA is then specified in a more technical form in a service level specification (SLS), which can conform to the specifications of the Internet engineering task force (IETF).
In other words, the SLS is derived from an SLA and contains the technical parameters that must be used to implement the service.
To provide a service on a telecommunication network, it is therefore necessary to set the network parameters to enable the service to be established, including compliance with the negotiated quality of service, for example.
The parameters can be set using policy rules, referred to for simplicity hereinafter as rules. The rules typically include a set of conditions and a set of actions. The sets can be reduced to a single element, i.e. a rule may consist of only one condition and/or only one action.
FIG. 1 shows how rules are implemented.
Conventionally, they are defined at the level of a policy manager (PM) and then transmitted to a policy server (PS). The policy server is responsible for their application by network elements which in this context are referred to as policy enforcement points (PEP).
The policy manager and the policy server are conventionally part of the network management layer (NML); to be more precise, they can belong to a network management system (NMS). However, it is important to note that a network may include only one of these elements, as the policy manager PM and the policy server PS can be two independent physical systems that can be marketed separately.
It is apparent that there is an important semantic difference between the definition of the service, for example in the context of an SLA/SLS, and the corresponding rules, which must be implemented by the network elements or PEP, in particular the configurations of the network elements.
In concrete terms, the difference can become apparent at two or more levels:
Firstly, it obliges the designer of the service to have network expert knowledge. For example, it is incumbent on the service designer to decide how a virtual private network VPN should be implemented, for example whether the IPsec protocol must be used, or if preference must be given to the multi-protocol label switching (MPLS) technology.
Secondly, it obliges the service designer to have access to the exact specifications of each network element to be configured. Depending on the manufacturer, the same type of network element (IP router, firewall, etc.) may be configured differently, because the capacities may be different.
The object of the present invention is to alleviate this drawback and to facilitate the development of new services by means of rules.